Mamool Ja's Broken English

[LilimoLimomo]

Almost every spoken race in Etheriys seems to conveniently know Common for...
I never really got the impression there was much of a language barrier between the beastmen and human races, though, as we see them communicating with non-Echo bearers rather routinely and the Gajasura tribe of the Matanga are the only ones specifically noted as having difficulty with the common tongue, which led to them being discriminated against by the Garleans.

In the 1.x story, all of the tribes spoke their own distinct languages that all but prohibited their ability to communicate with the "player races". Minfilia's organization at that time, The Path of the Twelve, had the goal of communicating with the tribes to try to facilitate peace; to achieve that goal, the organization was mostly made up of people with the Echo, since Echo-users can understand any sentient being regardless of language-barriers. And because of their ability to communicate with these tribes, at this point in the story Garlean policy treated those with the Echo as if they were members of these tribes (which is to say, they were free to oppress them).

However, by the time 2.0 comes around, nearly everyone is speaking the same language (or at least understanding each other). I'm not sure if there's explicit lore around this, but my interpretation has been that the additional soul density from the Rejoining somehow facilitated this new threshold of understanding.

So are we supposed to believe that the Mamool Ja who not only intermingle with other tribes but in fact do so on a day-to-day basis and rule their entire empire speak "Common" with a specific quirk while the other inhabitants of Tural do not? What are they too alien to properly learn the basic language of communication of their own homeland where they are perfectly integrated and make the king?

With respect, I think this is making a lot of assumptions about how monolithic the Mamool Ja are. It's entirely possible that Mamool Ja in Eorzea speak in a different dialect compared to Mamool Ja in Tural. For example, Sharlayans and Lominsans of the same race speak with wildly different dialects, and this follows with how language works in the real world, where the environment you were raised in is going to be the primary determining factor of how you speak, not your biology.

That said, if the writers decide that yes, all Mamool Ja talk the same, it wouldn't be a surprise because generally speaking that's how they often treat dialect; even in integrated communities, so-called "beast" races tend to speak in a distinct dialect compared to the "player races" that otherwise comprise their communities. I assume they think it adds spice to the writing, even if it defies sociology. Just remember that this game was written by imperfect humans who didn't entirely understand the ramifications of the words they wrote at the time they wrote them.